The PPE Standard has 5 levels of performance-- the "HOT" has more and is more aggressive. The PPE tuners can be loaded through the OBD II port in a few minutes, by anyone. No real learning curve. Probably the best canned tuner available. Price from [$450 and up] This is an easy sell if you upgrade in the future.
The EFI is a great tuner and can change many tables in the computer, and almost unlimited power added. Take a while to learn the program, and requires a laptop. More expensive than the PPE. Many vendors offer a re-program ECM, that you just exchange. Contact a vendor for more info.
Chevy 04.5 LLY, 2X, shell, XDR, MikeL Heavy duty up-grade, 6spd, TransGo, deep pan, de-badged, 65 Gallon replacement Aero tank, LBZ-mp, Kennedy pump, shimmed, Pre-fuel filter, tow mirrors, BU cam, gauges, GPS, Sirius, bags, custom grille, fender vents, HD trans cooler- Curt front hitch, footwell lights, load lights, Studs, head gaskets.